Irene Rothe,  An Idea About How to Teach OO-Programming to Students.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    June 2010, vol. 42(6). 1104 - 1107
    [viewed 25 January 2020]. Available from: https://publications.waset.org/pdf/7569.